Pipe fix

This is a bit of a dual update.  Tests have been added for the pipe_proc.tp function (and new logic), and a fix for pipe_proc.ext has been added, along with tests.  More details are in the commit messages.

I didn't want to add a new data file to the testing suite, so I use nmrPipe to FT the time_complex.fid file during the tests.  The scripts then delete the file.  Alternatively, I could just add the file to the testing suite.  Suggestions on this front are welcome.